http://www.sciencemag.org/news/2021/06/gives-hope-third-covid-19-vaccine-dose-can-boost-protection-organ-transplant-recipients

Science’s COVID-19 reporting is supported by the Heising-Simons Foundation.

A few months ago, transplant surgeon Dorry Segev was despondent about how COVID-19 vaccines were performing in patients like his, who have a donated organ and take powerful drugs to suppress their immune system. After one dose of a highly effective messenger RNA (mRNA) vaccine, for example, just 17% of those patients churned out protective antibodies against the pandemic coronavirus, and after the standard two doses, only 54% did. The very medications his patients took to protect their transplanted organ precluded them from mounting a healthy immune response after the vaccine. Even people who did make the antiviral antibodies often had very low levels, raising questions about how well they were shielded from COVID-19.